Union Iron Works

Union Iron Works, located in San Francisco, California, on the southeast waterfront, was a central business within the large industrial zone of Potrero Point, for four decades at the end of the nineteenth and beginning of the twentieth centuries.

[1] Peter Donohue, an Irish immigrant, founded Union Brass & Iron Works in the south of Market area of San Francisco in 1849.

After years as the premiere producer of mining, railroad, agricultural and locomotive[2] machinery in California, Union Iron Works, led by I. M. Scott, entered the ship building business and relocated to Potrero Point where its shipyards still exist, making the site on the north side of the Potrero the longest running privately owned shipyard in the United States.

In 1885, the Union Iron Works launched the first steel-hulled ship on the west coast, Arago, built with steel from the Pacific Rolling Mills.

[5] These industrial facilities used five types of power, distributed throughout; electricity, compressed air, steam, hydraulic and coal or gas fire.

[6] In 1902, the Union Iron Works was absorbed into a combine called the United States Shipbuilding Company and was mired in three years of litigation.